UGURUS offers elite coaching and mentorship for agency owners looking to grow. Start with the free Agency Accelerator today. Here’s a CSS variable (formally called a “CSS custom property“): :root { --mouse-x: 0px; --mouse-y: 0px; } Perhaps you use them to set a position: .mover { left: var(--mouse-x); top: var(--mouse-y); } To update those values from JavaScript, you’d: let root = document.documen